package com.itheima.d11_api_objects;

import com.itheima.d10_api_object.bean.User;

import java.util.Objects;

public class Test {
    public static void main(String[] args) {
        // 目标：掌握Objects类提供的常用方法。
        String s1 = null;
        String s2 = "itheima";

        /*if (s1 != null) {
            System.out.println(s1.equals(s2));
        }*/

        //避免空指针异常比较两个对象是否相同
        boolean equals = Objects.equals(s1, s2);
        System.out.println("equals = " + equals); //false

        User u1 = null;
        User u2 = new User();
//        System.out.println(u1.equals(u2)); //有空指针异常的风险
        System.out.println(Objects.equals(u1,u2)); //false

        //判断是否为空
        System.out.println(Objects.isNull(s1)); //true
        System.out.println(Objects.isNull(s2)); //false

        //判断不为空
        System.out.println(Objects.nonNull(s1)); //false
        System.out.println(Objects.nonNull(s2)); //ture

    }
}
